The instant invention relates generally to apparatus for turning flat articles and is particularly related to apparatus for turning envelopes.
Turning devices for flat articles that are conveyed horizontally are required in mail processing machines. Examples of flat articles include envelopes, letters, postcards, endless forms issued by a computer controlled printing device that are cut into sheets from an endless web, and the like. In an inserter and mail processing machine, sheets are fed, one by one or collected together, to a folding station and subsequently, with or without additional enclosures, are conveyed to an inserting station where the sheets are inserted into an envelope.
After insertion of the sheets into the envelope, the stuffed envelope is forwarded to a postage station where postage is imprinted thereon by a postage meter or printer. In certain inserters, it is necessary to turn the stuffed envelopes through a 90 degree angle if the postage meter or printer is oriented in the same direction as the discharge from the inserting station. Many types of turners are known in the prior art to effect a 90 degree turn, including the turner disclosed in U.S. Pat. No. 4,928,807 issued to the assignee of the instant invention. In the '807 patent, a spring loaded pivot ball is used to clamp the envelope being turned against an elastomeric disk situated beneath the envelope. It has been found that the '807 clamping mechanism would not clamp properly over the entire range of envelope pack thicknesses. Excessive forces were generated on the turner deck and helped cause excessive belt and turner deck wear and increased system amperge which affected motor function.
Accordingly, the instant invention was developed and provides a clamping arm which overcomes all of the problems associated with the '807 clamping mechanism.